The results above show that in general OpenJPA with H2 server is equivalent to EclipseLink with Derby server in persisting JPA entity objects to the database.

On the other hand, OpenJPA with H2 server is slower, for instance, when using graphs of objects with large transaction size. Comparing the normalized speed of OpenJPA with H2 database server (0.84) to the normalized speed of EclipseLink with Derby database server (1.7) reveals that in that case, OpenJPA with H2 server is 2.0 times slower than EclipseLink with Derby server.

The results above show that in general EclipseLink with Derby server is more efficient than OpenJPA with H2 server in retrieving JPA entity objects from the database.

A huge performance gap has been detected when using JPA element collections with small retrieval size. Comparing the normalized speed of OpenJPA with H2 database server (0.0022) to the normalized speed of EclipseLink with Derby database server (1.8) reveals that in that case, EclipseLink with Derby server is 818 times faster than OpenJPA with H2 server.

The results above show that in general EclipseLink with Derby server is much more efficient than OpenJPA with H2 server in executing the tested JPA queries. Comparing the normalized speed of OpenJPA with H2 database server (2.5) to the normalized speed of EclipseLink with Derby database server (17.3) reveals that in these tests, EclipseLink with Derby server is 6.9 times faster than OpenJPA with H2 server.

A huge performance gap has been detected when using multithreading with small retrieval size. Comparing the normalized speed of OpenJPA with H2 database server (0.98) to the normalized speed of EclipseLink with Derby database server (34.3) reveals that in that case, EclipseLink with Derby server is 35.0 times faster than OpenJPA with H2 server.

The results above show that in general EclipseLink with Derby server is more efficient than OpenJPA with H2 server in updating JPA entity objects in the database.

A huge performance gap has been detected when using JPA element collections with small transaction size. Comparing the normalized speed of OpenJPA with H2 database server (0.0078) to the normalized speed of EclipseLink with Derby database server (1.7) reveals that in that case, EclipseLink with Derby server is 218 times faster than OpenJPA with H2 server.

The results above show that in general EclipseLink with Derby server is slightly more efficient than OpenJPA with H2 server in deleting JPA entity objects from the database.

A huge performance gap has been detected when using JPA element collections with small transaction size. Comparing the normalized speed of OpenJPA with H2 database server (0.0060) to the normalized speed of EclipseLink with Derby database server (1.2) reveals that in that case, EclipseLink with Derby server is 200 times faster than OpenJPA with H2 server.

The results above show that in general EclipseLink with Derby server is more efficient than OpenJPA with H2 server in performing JPA database operations. Comparing the normalized speed of OpenJPA with H2 database server (3.0) to the normalized speed of EclipseLink with Derby database server (6.6) reveals that in these tests, EclipseLink with Derby server is 2.2 times faster than OpenJPA with H2 server.

A large performance gap has been detected when using JPA element collections with small transaction/retrieval size. Comparing the normalized speed of OpenJPA with H2 database server (0.93) to the normalized speed of EclipseLink with Derby database server (8.4) reveals that in that case, EclipseLink with Derby server is 9.0 times faster than OpenJPA with H2 server.